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On the Generation Algorithm of VRS Virtual Observations 被引量:3
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作者 WEI Erhu CHAI Hua +1 位作者 LIU Jingnan AN Zhiguo 《Geo-Spatial Information Science》 2007年第2期91-95,共5页
In the past few years, network RTK positioning technology, especially the VRS technology, has been widely used in some parts of China and in many countries around the world. The principle of the VRS technology is disc... In the past few years, network RTK positioning technology, especially the VRS technology, has been widely used in some parts of China and in many countries around the world. The principle of the VRS technology is discussed with corresponding formula deduction, and detailed descriptions and applications of VRS corrections and virtual observations generation algorithm are given. 展开更多
关键词 network-RTK MRS corrections generation algorithm virtual observation
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Solving open vehicle problem with time window by hybrid column generation algorithm 被引量:1
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作者 YU Naikang QIAN Bin +2 位作者 HU Rong CHEN Yuwang WANG Ling 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2022年第4期997-1009,共13页
This paper addresses the open vehicle routing problem with time window(OVRPTW), where each vehicle does not need to return to the depot after completing the delivery task.The optimization objective is to minimize the ... This paper addresses the open vehicle routing problem with time window(OVRPTW), where each vehicle does not need to return to the depot after completing the delivery task.The optimization objective is to minimize the total distance. This problem exists widely in real-life logistics distribution process.We propose a hybrid column generation algorithm(HCGA) for the OVRPTW, embedding both exact algorithm and metaheuristic. In HCGA, a label setting algorithm and an intelligent algorithm are designed to select columns from small and large subproblems, respectively. Moreover, a branch strategy is devised to generate the final feasible solution for the OVRPTW. The computational results show that the proposed algorithm has faster speed and can obtain the approximate optimal solution of the problem with 100 customers in a reasonable time. 展开更多
关键词 open vehicle routing problem with time window(OVRPTW) hybrid column generation algorithm(HCGA) mixed integer programming label setting algorithm
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ALGORITHMS FOR TETRAHEDRAL NETWORK(TEN) GENERATION 被引量:11
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作者 LI Qingquan LI Deren 《Geo-Spatial Information Science》 2000年第1期11-16,共6页
The Tetrahedral Network(TEN) is a powerful 3-D vector structure in GIS, which has a lot of advantages such as simple structure, fast topological relation processing and rapid visualization. The difficulty of TEN appli... The Tetrahedral Network(TEN) is a powerful 3-D vector structure in GIS, which has a lot of advantages such as simple structure, fast topological relation processing and rapid visualization. The difficulty of TEN application is automatic creating data structure. Although a raster algorithm has been introduced by some authors, the problems in accuracy, memory requirement, speed and integrity are still existent. In this paper, the raster algorithm is completed and a vector algorithm is presented after a 3-D data model and structure of TEN have been introducted. Finally, experiment, conclusion and future work are discussed. 展开更多
关键词 3-D GIS tetrahedral network(TEN) generation algorithm
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Short-term power generation scheduling rules for cascade hydropower stations based on hybrid algorithm 被引量:2
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作者 Wei XIE Chang-ming JI +1 位作者 Zi-jun YANG Xiao-xing ZHANG 《Water Science and Engineering》 EI CAS 2012年第1期46-58,共13页
Power generation dispatching is a large complex system problem with multi-dimensional and nonlinear characteristics. A mathematical model was established based on the principle of reservoir operation. A large quantity... Power generation dispatching is a large complex system problem with multi-dimensional and nonlinear characteristics. A mathematical model was established based on the principle of reservoir operation. A large quantity of optimal scheduling processes were obtained by calculating the daily runoff process within three typical years, and a large number of simulated daily runoff processes were obtained using the progressive optimality algorithm (POA) in combination with the genetic algorithm (GA). After analyzing the optimal scheduling processes, the corresponding scheduling rules were determined, and the practical formulas were obtained. These rules can make full use of the rolling runoff forecast and carry out the rolling scheduling. Compared with the optimized results, the maximum relative difference of the annual power generation obtained by the scheduling rules is no more than 1%. The effectiveness and practical applicability of the scheduling rules are demonstrated by a case study. This study provides a new perspective for formulating the rules of power generation dispatching. 展开更多
关键词 scheduling rule short-time power generation dispatching hybrid algorithm cascade hydropower station
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Genetic Algorithms of Structural Fuzzy Reliability Index
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作者 Hu, YC Li, XJ Zhang, LY 《China Ocean Engineering》 SCIE EI 1998年第1期33-42,共10页
In this paper the simple generation algorithms are improved. According to the geometric meaning of the structural reliability index, a method is proposed to deal with the variables in the standard normal space. With c... In this paper the simple generation algorithms are improved. According to the geometric meaning of the structural reliability index, a method is proposed to deal with the variables in the standard normal space. With consideration of variable distribution, the correlation coefficient of the variables and its fuzzy reliability index, the feasibility and the reliability of the algorithms are proved with an example of structural reliability analysis and optimization. 展开更多
关键词 structural fuzzy reliability index generation algorithm reliability analysis and optimization correlation coefficient normal space
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An efficient algorithm for generating a spherical multiple-cell grid
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作者 Fang Hou Zhiyi Gao +1 位作者 Jianguo Li Fujiang Yu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2022年第5期41-50,共10页
This paper presents an efficient algorithm for generating a spherical multiple-cell(SMC)grid.The algorithm adopts a recursive loop structure and provides two refinement methods:(1)an arbitrary area refinement method a... This paper presents an efficient algorithm for generating a spherical multiple-cell(SMC)grid.The algorithm adopts a recursive loop structure and provides two refinement methods:(1)an arbitrary area refinement method and(2)a nearshore refinement method.Numerical experiments are carried out,and the results show that compared with the existing grid generation algorithm,this algorithm is more flexible and operable. 展开更多
关键词 spherical multiple-cell grid wave model WAVEWATCH III grid generation algorithm
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Optimization of volume to point conduction problem based on a novel thermal conductivity discretization algorithm
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作者 杜文静 王沛丽 +1 位作者 宋立鹏 程林 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第7期1161-1168,共8页
A conduction heat transfer process is enhanced by filling prescribed quantity and optimized-shaped high thermal conductivity materials to the substrate. Numerical simulations and analyses are performed on a volume to ... A conduction heat transfer process is enhanced by filling prescribed quantity and optimized-shaped high thermal conductivity materials to the substrate. Numerical simulations and analyses are performed on a volume to point conduction problem based on the principle of minimum entropy generation. In the optimization, the arrangement of high thermal conductivity materials is variable, the quantity of high thermal-conductivity material is constrained, and the objective is to obtain the maximum heat conduction rate as the entropy is the minimum.A novel algorithm of thermal conductivity discretization is proposed based on large quantity of calculations.Compared with other algorithms in literature, the average temperature in the substrate by the new algorithm is lower, while the highest temperature in the substrate is in a reasonable range. Thus the new algorithm is feasible. The optimization of volume to point heat conduction is carried out in a rectangular model with radiation boundary condition and constant surface temperature boundary condition. The results demonstrate that the algorithm of thermal conductivity discretization is applicable for volume to point heat conduction problems. 展开更多
关键词 Volume to point conduction Principle of minimum entropy generation algorithm of thermal conductivity discretization Optimization
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Optimization of multi-color laser waveform for high-order harmonic generation 被引量:1
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作者 金成 林启东 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第9期157-168,共12页
With the development of laser technologies,multi-color light-field synthesis with complete amplitude and phase control would make it possible to generate arbitrary optical waveforms.A practical optimization algorithm ... With the development of laser technologies,multi-color light-field synthesis with complete amplitude and phase control would make it possible to generate arbitrary optical waveforms.A practical optimization algorithm is needed to generate such a waveform in order to control strong-field processes.We review some recent theoretical works of the optimization of amplitudes and phases of multi-color lasers to modify the single-atom high-order harmonic generation based on genetic algorithm.By choosing different fitness criteria,we demonstrate that:(i) harmonic yields can be enhanced by 10 to 100 times,(ii) harmonic cutoff energy can be substantially extended,(iii) specific harmonic orders can be selectively enhanced,and(iv) single attosecond pulses can be efficiently generated.The possibility of optimizing macroscopic conditions for the improved phase matching and low divergence of high harmonics is also discussed.The waveform control and optimization are expected to be new drivers for the next wave of breakthrough in the strong-field physics in the coming years. 展开更多
关键词 high-order harmonic generation waveform optimization genetic algorithm single-attosecond pulse
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Complete Real Solution of the Five-orientation Motion Generation Problem for a Spherical Four-bar Linkage 被引量:1
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作者 ZHUANG Yufeng ZHANG Ying DUAN Xuechao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第2期258-266,共9页
For a spherical four-bar linkage,the maximum number of the spherical RR dyad(R:revolute joint)of five-orientation motion generation can be at most 6.However,complete real solution of this problem has seldom been st... For a spherical four-bar linkage,the maximum number of the spherical RR dyad(R:revolute joint)of five-orientation motion generation can be at most 6.However,complete real solution of this problem has seldom been studied.In order to obtain six real RR dyads,based on Strum's theorem,the relationships between the design parameters are derived from a 6th-degree univariate polynomial equation that is deduced from the constraint equations of the spherical RR dyad by using Dixon resultant method.Moreover,the Grashof condition and the circuit defect condition are taken into account.Given the relationships between the design parameters and the aforementioned two conditions,two objective functions are constructed and optimized by the adaptive genetic algorithm(AGA).Two examples with six real spherical RR dyads are obtained by optimization,and the results verify the feasibility of the proposed method.The paper provides a method to synthesize the complete real solution of the five-orientation motion generation,which is also applicable to the problem that deduces to a univariate polynomial equation and requires the generation of as many as real roots. 展开更多
关键词 spherical four-bar linkage five-orientation motion generation Sturm's theorem adaptive genetic algorithm(AGA
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Health Data Deduplication Using Window Chunking-Signature Encryption in Cloud
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作者 G.Neelamegam P.Marikkannu 《Intelligent Automation & Soft Computing》 SCIE 2023年第4期1079-1093,共15页
Due to the development of technology in medicine,millions of health-related data such as scanning the images are generated.It is a great challenge to store the data and handle a massive volume of data.Healthcare data ... Due to the development of technology in medicine,millions of health-related data such as scanning the images are generated.It is a great challenge to store the data and handle a massive volume of data.Healthcare data is stored in the cloud-fog storage environments.This cloud-Fog based health model allows the users to get health-related data from different sources,and duplicated informa-tion is also available in the background.Therefore,it requires an additional sto-rage area,increase in data acquisition time,and insecure data replication in the environment.This paper is proposed to eliminate the de-duplication data using a window size chunking algorithm with a biased sampling-based bloomfilter and provide the health data security using the Advanced Signature-Based Encryp-tion(ASE)algorithm in the Fog-Cloud Environment(WCA-BF+ASE).This WCA-BF+ASE eliminates the duplicate copy of the data and minimizes its sto-rage space and maintenance cost.The data is also stored in an efficient and in a highly secured manner.The security level in the cloud storage environment Win-dows Chunking Algorithm(WSCA)has got 86.5%,two thresholds two divisors(TTTD)80%,Ordinal in Python(ORD)84.4%,Boom Filter(BF)82%,and the proposed work has got better security storage of 97%.And also,after applying the de-duplication process,the proposed method WCA-BF+ASE has required only less storage space for variousfile sizes of 10 KB for 200,400 MB has taken only 22 KB,and 600 MB has required 35 KB,800 MB has consumed only 38 KB,1000 MB has taken 40 KB of storage spaces. 展开更多
关键词 Health data ENCRYPTION chunks CLOUD FOG DEDUPLICATION bloomfilter algorithm 3:generation of Key
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Graph-Theoretic Approach to Network Analysis
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作者 Nabil Hassan 《Computer Technology and Application》 2013年第12期625-634,共10页
Networks are a class of general systems represented by becomes a weighted graph visualizing the constraints imposed their UC-structure. Suppressing the nature of elements the network by interconnections rather than th... Networks are a class of general systems represented by becomes a weighted graph visualizing the constraints imposed their UC-structure. Suppressing the nature of elements the network by interconnections rather than the elements themselves. These constraints follow generalized Kirchhoff's laws derived from physical constraints. Once we have a graph; then the working environment becomes the graph-theory. An algorithm derived from graph theory is developed within the paper in order to analyze general networks. The algorithm is based on computing all the spanning trees in the graph G with an associated weight. This weight is the product ofadmittance's of the edges forming the spanning tree. In the first phase this algorithm computes a depth first spanning tree together with its cotree. Both are used as parents for controlled generation of off-springs. The control is represented in selecting the off-springs that were not generated previously. While the generation of off-springs, is based on replacement of one or more tree edges by cycle edges corresponding to cotree edges. The algorithm can generate a frequency domain analysis of the network. 展开更多
关键词 UC-structure NETWORK spanning tree depth-first search spanning trees generation algorithm.
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A Complete Critical Path Algorithm for Test Generation of Combinational Circuits
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作者 周权 魏道政 《Journal of Computer Science & Technology》 SCIE EI CSCD 1991年第1期74-82,共9页
It is known that critical path test generation method is not a complete algorithm for combinational circuits with reconvergent-fanout.In order to make it a complete algorithm,we put forward a reconvergent-fanout- orie... It is known that critical path test generation method is not a complete algorithm for combinational circuits with reconvergent-fanout.In order to make it a complete algorithm,we put forward a reconvergent-fanout- oriented technique,the principal critical path algorithm,propagating the critical value back to primary inputs along a single path,the principal critical path,and allowing multiple path sensitization if needed.Relationship among test patterns is also discussed to accelerate test generation. 展开更多
关键词 PATH A Complete Critical Path algorithm for Test generation of Combinational Circuits TEST
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Multi-objective optimization of cooling air distribution of grate cooler with different inlet temperatures by using genetic algorithm 被引量:4
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作者 SHAO Wei CUI Zheng CHENG Lin 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2017年第3期345-354,共10页
The paper discussed a multi-objective optimization model of the cooling air distribution of a grate cooler according to the analogy
关键词 cooling air distribution grate cooler multi-objective genetic algorithm entropy generation
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Generation method of minimal-complete-coverage interoperability test sequence based on digraph
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作者 LIN Huahui ZHAO Baohua QU Yugui 《Frontiers of Electrical and Electronic Engineering in China》 CSCD 2007年第1期29-33,共5页
Even if two implementations of a protocol pass the conformance testing,it cannot guarantee that they can interoperate properly;so direct testing of interoperation is considered indispensable.During the interoperabilit... Even if two implementations of a protocol pass the conformance testing,it cannot guarantee that they can interoperate properly;so direct testing of interoperation is considered indispensable.During the interoperability testing,a minimal number of test sequences are expected to check as many as possible implementation errors.By using minimal-complete-coverage criterion,the test sequence generation based on digraph can produce more effective test sequences. 展开更多
关键词 interoperability test interoperability equiva-lence minimal-complete-coverage criterion algorithm of test sequence generation DIGRAPH
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A Machine Learning-Based Botnet Malicious Domain Detection Technique for New Business
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作者 Aohan Mei Zekun Chen +1 位作者 Jing Zhao Dequan Yang 《国际计算机前沿大会会议论文集》 EI 2023年第2期191-201,共11页
In the new network business,the danger of botnets should not be underestimated.Botnets often generatemalicious domain names through DGAs to enable communication with command and control servers(C&C)and then receiv... In the new network business,the danger of botnets should not be underestimated.Botnets often generatemalicious domain names through DGAs to enable communication with command and control servers(C&C)and then receive commands from the botmaster,carrying out further attack activities.Therefore,a system based onmachine learning to dichotomizeDNSdomain access is designed,which can instantly detectDGAdomain names and thus quickly dispose of infected computers to avoid spreading the virus and further damage.In the comparison,the bidirectional LSTM model slightly outperformed the unidirectional LSTM network and achieved 99%accuracy in the open dataset classification task. 展开更多
关键词 BOTNET Machine Learning LSTM Domain generation algorithm Detection
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A DGA domain names detection modeling method based on integrating an attention mechanism and deep neural network 被引量:9
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作者 Fangli Ren Zhengwei Jiang +1 位作者 Xuren Wang Jian Liu 《Cybersecurity》 CSCD 2020年第1期71-83,共13页
Command and control(C2)servers are used by attackers to operate communications.To perform attacks,attackers usually employee the Domain Generation Algorithm(DGA),with which to confirm rendezvous points to their C2 ser... Command and control(C2)servers are used by attackers to operate communications.To perform attacks,attackers usually employee the Domain Generation Algorithm(DGA),with which to confirm rendezvous points to their C2 servers by generating various network locations.The detection of DGA domain names is one of the important technologies for command and control communication detection.Considering the randomness of the DGA domain names,recent research in DGA detection applyed machine learning methods based on features extracting and deep learning architectures to classify domain names.However,these methods are insufficient to handle wordlist-based DGA threats,which generate domain names by randomly concatenating dictionary words according to a special set of rules.In this paper,we proposed a a deep learning framework ATT-CNN-BiLSTMfor identifying and detecting DGA domains to alleviate the threat.Firstly,the Convolutional Neural Network(CNN)and bidirectional Long Short-Term Memory(BiLSTM)neural network layer was used to extract the features of the domain sequences information;secondly,the attention layer was used to allocate the corresponding weight of the extracted deep information from the domain names.Finally,the different weights of features in domain names were put into the output layer to complete the tasks of detection and classification.Our extensive experimental results demonstrate the effectiveness of the proposed model,both on regular DGA domains and DGA that hard to detect such as wordlist-based and part-wordlist-based ones.To be precise,we got a F1 score of 98.79%for the detection and macro average precision and recall of 83%for the classification task of DGA domain names. 展开更多
关键词 Domain generation algorithm MALWARE Attention mechanism Deep learning
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DGA-Based Botnet Detection Toward Imbalanced Multiclass Learning 被引量:4
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作者 Yijing Chen Bo Pang +2 位作者 Guolin Shao Guozhu Wen Xingshu Chen 《Tsinghua Science and Technology》 SCIE EI CAS CSCD 2021年第4期387-402,共16页
Botnets based on the Domain Generation Algorithm(DGA) mechanism pose great challenges to the main current detection methods because of their strong concealment and robustness. However, the complexity of the DGA family... Botnets based on the Domain Generation Algorithm(DGA) mechanism pose great challenges to the main current detection methods because of their strong concealment and robustness. However, the complexity of the DGA family and the imbalance of samples continue to impede research on DGA detection. In the existing work, the sample size of each DGA family is regarded as the most important determinant of the resampling proportion;thus,differences in the characteristics of various samples are ignored, and the optimal resampling effect is not achieved.In this paper, a Long Short-Term Memory-based Property and Quantity Dependent Optimization(LSTM.PQDO)method is proposed. This method takes advantage of LSTM to automatically mine the comprehensive features of DGA domain names. It iterates the resampling proportion with the optimal solution based on a comprehensive consideration of the original number and characteristics of the samples to heuristically search for a better solution around the initial solution in the right direction;thus, dynamic optimization of the resampling proportion is realized.The experimental results show that the LSTM.PQDO method can achieve better performance compared with existing models to overcome the difficulties of unbalanced datasets;moreover, it can function as a reference for sample resampling tasks in similar scenarios. 展开更多
关键词 BOTNET Domain generation algorithm(DGA) multiclass imbalance RESAMPLING
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A highly efficient reconfigurable rotation unit based on an inverse butterfly network
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作者 Chao MA Zi-bin DAI +1 位作者 Wei LI Hai-juan ZANG 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2017年第11期1784-1794,共11页
We propose a reeonfigurable control-bit generation algorithm for rotation and sub-word rotation operations. The algorithm uses a self-routing characteristic to configure an inverse butterfly network. In addition to be... We propose a reeonfigurable control-bit generation algorithm for rotation and sub-word rotation operations. The algorithm uses a self-routing characteristic to configure an inverse butterfly network. In addition to being highly parallelized and inexpensive, the algorithm integrates the rotation-shift, bi-directional rotation-shift, and sub-word rotation-shift operations. To our best knowledge, this is the first scheme to accommodate a variety of rotation operations into the same architecture. We have developed the highly efficient reconfigurable rotation unit (HERRU) and synthesized it into the Semiconductor Manufacturing International Corporation (SMIC)'s 65-nm process. The results show that the overall efficiency (relative areaxrelative latency) of our HERRU is higher by at least 23% than that of other designs with similar functions. When executing the bi-directional rotation operations alone, HERRU occupies a significantly smaller area with a lower latency than previously proposed designs. 展开更多
关键词 Rotation operations Self-routing Control-bit generation algorithm Inverse butterfly network
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A DGA domain names detection modeling method based on integrating an attention mechanism and deep neural network
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作者 Fangli Ren Zhengwei Jiang +1 位作者 Xuren Wang Jian Liu 《Cybersecurity》 2018年第1期697-709,共13页
Command and control(C2)servers are used by attackers to operate communications.To perform attacks,attackers usually employee the Domain Generation Algorithm(DGA),with which to confirm rendezvous points to their C2 ser... Command and control(C2)servers are used by attackers to operate communications.To perform attacks,attackers usually employee the Domain Generation Algorithm(DGA),with which to confirm rendezvous points to their C2 servers by generating various network locations.The detection of DGA domain names is one of the important technologies for command and control communication detection.Considering the randomness of the DGA domain names,recent research in DGA detection applyed machine learning methods based on features extracting and deep learning architectures to classify domain names.However,these methods are insufficient to handle wordlist-based DGA threats,which generate domain names by randomly concatenating dictionary words according to a special set of rules.In this paper,we proposed a a deep learning framework ATT-CNN-BiLSTMfor identifying and detecting DGA domains to alleviate the threat.Firstly,the Convolutional Neural Network(CNN)and bidirectional Long Short-Term Memory(BiLSTM)neural network layer was used to extract the features of the domain sequences information;secondly,the attention layer was used to allocate the corresponding weight of the extracted deep information from the domain names.Finally,the different weights of features in domain names were put into the output layer to complete the tasks of detection and classification.Our extensive experimental results demonstrate the effectiveness of the proposed model,both on regular DGA domains and DGA that hard to detect such as wordlist-based and part-wordlist-based ones.To be precise,we got a F1 score of 98.79% for the detection and macro average precision and recall of 83% for the classification task of DGA domain names. 展开更多
关键词 Domain generation algorithm MALWARE Attention mechanism Deep learning
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Construction of Multimodal Chinese Tourism Knowledge Graph
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作者 Jiawang Xie Zhenhao Dong +4 位作者 Qinghua Wen Hongyin Zhu Hailong Jin Lei Hou Juanzi Li 《国际计算机前沿大会会议论文集》 2021年第2期16-29,共14页
With the development of tourism knowledge graphs(KGs),recommendation,question answering(QA)and other functions under its support enable various applications to better understand users and provide services.Existing Chi... With the development of tourism knowledge graphs(KGs),recommendation,question answering(QA)and other functions under its support enable various applications to better understand users and provide services.Existing Chinese tourism KGs do not contain enough entity information and relations.Besides,the knowledge storage usually contains only the text modality but lacks other modalities such as images.In this paper,a multi-modal Chinese tourism knowledge graph(MCTKG)is proposed based on Beijing tourist attractions to support QA and help tourists plan tourism routes.An MCTKG ontology was constructed to maintain the semantic consistency of heterogeneous data sources.To increase the number of entities and relations related to the tourist attractions in MCTKG,entities were automatically expanded belonging to the concepts of building,organization,relic,and person based on Baidu Encyclopedia.In addition,based on the types of tourist attractions and the styles of tourism route,a tourism route generation algorithm was proposed,which can automatically schedule the tourism routes by incorporating tourist attractions and the route style.Experimental results show that the generated tourist routes have similar satisfaction comparedwith the tourism routes crawled from specific travel websites. 展开更多
关键词 Knowledge graph Tourism ontology Entity expansion Route generation algorithm
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